Charlene Wolf-Hall
  Charlene
Wolf-Hall remembers being eight or so and watching steam rising from silage
piles on her family’s South Dakota farm (near Mitchell). She believes
an interest in scientific inquiry was planted as her father explained
to her the processes of fermentation. She became a farmyard scientist,
experimenting with molds, fermentation, and decomposition as she collected
silage, grain and discarded food samples and cultured colonies of molds
in jars and bottles. Her parents, she says, were tolerant, as long as
her “work” remained outdoors.
Today, Wolf-Hall is an Associate Professor of Food Microbiology in
the Department of Veterinary and Microbiological Sciences. Her Ph.D.,
from
University of Nebraska-Lincoln (1995) in Food Science and Technology
with an emphasis in Food Microbiology and Food Toxicology, built upon
her Bachelors and her Masters degrees in Microbiology from South Dakota
State University in Brookings. Although she is now on an 85% research
contract, she has taught a wide variety of courses, mainly in interdisciplinary
food science and food safety areas. Wolf-Hall’s teaching has been
positively recognized by students, who nominated her for Carnegie Professor
(these were nominations by the teaching academy, not students) of the
Year in 2005, and to deliver a “Last Lecture” in 2000.
Wolf-Hall’s childhood interest in molds and fermentation still
drives her research, which is far more sophisticated now. As a food microbiologist,
she now studies microorganisms in food, and specifically works with molds
in grain, culturing molds and screening for toxins. The importance of
this work is in beginning to understand how these molds cause disease
in humans and animals, and how food scientists can interrupt that process.
With her dissertation research she began her work with the mycotoxin-producing
mold, Fusarium graminearium, as it affects corn and wheat. (Fusarium
graminearium produces the condition commonly known as wheat scab.) Wolf-Hall’s
research differs from that of plant pathologists in that she is interested
in exploring post-harvest methods for dealing with mycotoxincontaminated
grain. This will help ensure the safety of the grain, and salvaging contaminated
grain for higher end use could greatly improve the economic outcome for
regions severely affected by pre-harvest plant diseases or grain storage
and processing problems.
Because the science that drives this research is interdisciplinary,
Wolf-Hall regularly works with cereal scientists, engineers and economists.
A recent project has allowed her to work with the malting and beer brewing
industries to understand and control Fusarium in the barley used for
making malt (and brewing beer). The goal of this research is to reduce
toxin production, which can increase during the fermentation process,
while saving the grain, without quality reduction, harm to the yeast,
or the use of unsafe chemicals. Wolf-Hall’s team has developed
unique ways to process barley using hot water or electron beam radiation.
In addition, they have experimented with two chemicals, ozone and hydrogen
peroxide, both of which are already approved for organic processing because
they break down so easily.
 This research has placed Wolf-Hall among a small number of scientists
who work at the intersection of microbiology and cereal science, as grain
microbiologists. She has become an invited consultant for the Scientific
Advisory Panel for the American Association of Cereal Chemists. As part
of this work she is regularly consulted by industry. For example, in
2001, after several wet harvest years, she received calls from milling
companies who had had their flour rejected on the international market
because of high microbe levels. Because the criteria for normal loads
had been established during a period of drought, Wolf-Hall hypothesized
that grain harvest in wetter conditions, and not problems with the flour,
were leading to the higher loads in the flour. Her research sought to
collect data from different harvest conditions to understand what the
range of “normal” across harvest conditions might be, and
to catalogue microbial load in raw grain, flour, and processed products
like pasta and bread. The project also helps characterize the types of
microbes (good, bad or ugly) in the harvested grain and processed products.
This research has led to a series of published articles and abstracts
as well as conference presentations.
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